Pen



#lh-'28, 1969 FRIEDRICH-WILHELM RAuscH 3,424,538

PEN

Filed Sept. l2, 1966 United States Patent O 3,424,538 PENFriedrich-Wilhelm Rausch, Hannover, Germany, assignor to Wagner GuentherPelikan-Werke, Hannover, Germany Filed Sept. 12, 1966, Ser. No. 578,578Claims priority, application Germany, Aug. 16, 1966,

W 39,925 U.s. C1. 401-259 claims Inf. cl. 43k 5/00,1/06

ABSTRACT 0F THE DISCLOSURE A pen includes a barrel having a central boreat its front end and rearwardly thereof a centrally arranged closedcylindrical chamber having a narrow opening at its front end coaxialwith the bore. An ink reservoir is located rearwardly of the cylindricalchamber. The

ink reservoir and the cylindrical chamber are separated by wall means.Passage means extends in the barrel alongside the cylindrical chamberand communicates with the ink reservoir and with the bore. An inkapplicator is removably mounted on the front end of the barrel andprovided with a central passage coaxial with the bore and the narrowopening. A cleaning unit comprises a piston element slidably arranged inthe cylindrical chamber and a pin secured to and extending forwardly ofthe piston element so that, when the latter is in advanced position thepin projects through the narrow opening and the bore into the centralpassage in the ink applicator.

The present invention relates to a pen and, more particularly, to a penhaving a rellable ink reservoir.

Pens of the type having a refllable ink reservoir are generally known asfountain pens, a designation which will occasionally be employedhereafter. All pens of this type are provided with nibs of one type oranother which contact the paper and make thereon the ink indicia. Someof the general-use fountain pens, and most fountain pens used fordrafting, are provided with nibs in form of a short tubular portionthrough which ink can ow from the reservoir onto the paper or othermaterial on which indicia are to be made. The problem with this lattertype of nib is, however, that quantities of ink are likely to drythereon, or indeed to dry in the passages connecting the tubular memberwith the ink reservoir. This is particularly true in the case offountain pens which are to be used for drafting purposes since thesepens utilize india ink which, having a higher solids content thanregular inks, is especially susceptible to forming encrustations whichadversely influence or perhaps even completely prevent the further flowof ink.

Attempts have been made to overcome this and in one of these apiston-like member is disposed in a chamber in the interior of thedetachable ink applicator carried by the pen, and provided with aforwardly projecting pin which is located within the tubular nib of theapplicator and can freely move therein in longitudinal direction inresponse to any movement of the pen from a horizontal to an inclinedposition, or vice versa. In constructions of this type there is verylittle provision made for displacement of the ink when expansion of theair in the ink reservoir occurs. Accordingly, pens constructed in thismanner are susceptible to smudging, since ink which is being displacedby expanding air in the reservoir, can escape only to the outside of thepen and not to an auxiliary reservoir wherein it might be collected.Furthermore, the construction of these pens is conducive to theformation of ink encrustations and requires frequent dissassembly of thepen and cleaning of the writing portions. Addi- 3,424,538 Patented Jan.28, 1969 ICC tionally, the construction of pens of this type isrelatively expensive.

In another type of drafing pen the front portion, including the inkapplicator, comprises an auxiliary ink reservoir of relatively greatvolume which is connected with an ink feeding system. The arrangementand configuration of the ink reservoir or reservoirs makes possible arelatively advantageous compensation for temperature fluctuations andthus relatively uniform ink ow. However, in these devices the movablepiston-like member with its pin is not provided since the spacenecessary for it is of course taken up by the auxiliary or overlflowreservoir. Thus, the formation of encrustations within the tubular nibis inevitable and the pen must then be disassembled and cleaned. This israther ditlicult because of the relative complexity of the ink feedingsystem connecting the nib with the overow reservoir.

It is therefore a general object of the present invention to provide apen as set forth above which is not subject to the disadvantages of theprior art.

A more specific object of the present invention is to provide such a penin which the formation of encrustations in the nib is eliminated or atleast largely prevented.

A concomitant object of the invention is to provide a pen of the typeoutlined above in which a uniform ink ow from the ink reservoir to thenib is assured.

In accordance with one feature of my invention I provide a pen whichcomprises an elongated pen barrel provided at its front end with acentral bore and rearwardly therefrom with a centrally arranged closedcylindrical chamber having a narrow opening at its front end arrangedcoaxially with said central bore. An ink reservoir is provided in thebarrel and is located rearwardly of the cylindrical chamber separatedtherefrom. Passage means are provided in the barrel, including a portionwhich extends alongside of and is spaced from the cylindrical chamberand communicates at one end with the ink reservoir and at its other endwith the bore at the front end of the barrel, an ink applicator isremovably mounted on the front end of the barrel Iand is provided with acentral passage arranged coaxially with the bore and the narrow opening,and a cleaning unit is provided, including a piston element slidablyarranged within the cylindrical chamber and movable between a retractedposition nearer to the ink reservoir and in an advanced position nearerto the narrow opening of the cylindrical chamber. The cleaning unitfurther includes a pin which is secured at its rear end to the pistonelement and extends forwardly therefrom, such pin projecting in advancedposition of the piston element through the narrow opening and the borein the front end of the barrel into the central passage of the inkapplicator.

In accordance with an important feature of the invention the length ofthe path along which the piston-like member can move, as well as thelength of the pin are so arranged that in the retracted position of thepiston-like element the front end of the pin is located within thecentral bore in the front end of the barrel. Thus, the ink applicatorcan be readily exchanged for an applicator of different type while thepiston-like element is in retracted position without fear of damagingthe delicate pin. On the other hand, when the piston-like element movesto its advanced position the pin will project into the nib of the inkapplicator. Thus, any movement of the pen from a horizontal to aninclined position and vice versa will cause shifting of the piston-likeelement and consequently of the pin into and out of the nib of the inkapplicator, thereby cleaning this nib of ink deposits or encrustations.

In accordance with the invention it is important that the space Withinwhich the piston-like element is slid- \f encrustations which might tendto preclude movement of the piston-like element.

Also the ink is in contact with the air only at the point :at which itleaves the front end of the nib, so that the formation of inkencrustations is further reduced by this expedient.

Furthermore, the invention provides for an auxiliary or overflow inkreservoir of relatively great volume which permits use of the pen underall atmospheric conditions `without any significant changes in the inkow.

The novel features which are considered as characteris tic for theinvention are set forth in particular in the ap pended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawings, inwhich:

FIG. 1 is a partial cross-section in longitudinal direction through apen in accordance with the present invention; and

FIG. 2 is a section taken on the line II-II of FIG. l.

Discussing now the drawing in detail, and firstly FIG. 1 thereof, itwill -be seen that the front section 1 of the pen is provided with aninternal shoulder 2 and is connected via screw threads 3 with a rearportion of the barrel, namely with an ink reservoir-containing portion6. An elastically compressible sealing ring 8 is advanta geouslyprovided which is compressed between the por tions 1 and 6. Byconstructing the face 11 at the front end of the rear portion 6 inforwardly slanting direction the sealing action becomes particularlyeffective.

The front portion 1 houses an inner sleeve comprising a back portion 4and a forward portion 5. Located within this inner sleeve is a guidesleeve 7. The inner sleeve is provided with a radially projecting angeportion 9 which is received within the front portion 1 of the barrel andwhich is provided with an eccentrically located annular capillary groove10 which at its narrowest point as seen with respect to the Ibore offront portion 1 is connected with the interior of the ink reservoir `6by a longitudinally extending groove 12 whereas at its widest,oppositely located point it is connected via a longitudinally extendinggroove 13 with an overflow reservoir 18. The back portion 4 is providedat its forward end with a means for securing thereto the forward portion5, for instance by pushing the front end of the portion 4 into therearwardly directed opening of the forward portion 5.

The forward portion 5 is provided with two or more annular grooves 14and 15 which are in communication with one another and which furthercommunicate via an air chamber 16 with the ambient atmosphere and via anadditional air channel 17 with the overflow reservoir 18. None of thesechannels are of capillary type.

The forward portion 5 is `also provided `with a radial shoulder 19 whichengages the inwardly directed shoulder 2 at the front end of portion 1against which it is pressed when the sealing ring 8 is placed -underaxial compression, as has been indicated before.

Guide sleeve 7 is located within the portions 4 and 5 and extends overthe entire length thereof in such a manner that an annular capillarypassage 20 exists between the inner wall of the portions 4 and 5 on theone hand and the outer wall of the drive sleeve 7 on the other hand.This passage 20 serves for conducting the ink.

The guide sleeve 7 is, as will be evident from the drawing, centered andsupported, preferably at its conically tapering front end, by supportingprojections 21 provided at the conically tapering bore of portion 5, andthe depth of these projections 21 is such that a capillary passage isformed between the same and the sleeve 7. At the rearward end the sleeve7 is secured and centered by having an axial projection 22 provided onthe back portion 4 extending into its central chamber 32. Of course,this axial projection 22 simultaneously serves to close off the rear endof sleeve 7 and to thus define the aforementioned central chamber 32.

The cleaning unit, comprising an axially slidable piston member 23 whichcarries at its front end a forwardly projecting pin 24, is slidablewithin this chamber 32. When the novel pin is tilted such that itsforward end points in downward direction the piston member 23 moves toan advanced position in which the pin projects through the bore 25 ofsleeve 7 into the bore 26, which is of greater cross-section than thebore 25 since through bore 26 ink must ow whereas it is desired thatink-flow through bore 25 be prevented, and into the tubular nib 27 ofthe ink applicator 28. The total length of the pin 24 and the piston 23,as well as the extent of axial movement of the latter, are so arrangedthat in the retracted position of the piston 23 the front end of the pin24 does not project beyond the bore 26 and is thus protected if the inkapplicator 28 is exchanged or removed, whereas in advanced position ofthe piston 23 the pin extends completely through the nib 27 and slightlyprojects beyond the open front end thereof.

As is evident from the drawing the outer wall of back portion 4 is notcylindrical but rather slightly conical in such manner that it taperstowards the front of the pen. A particularly advantageous capillaryaction can be obtained in this area if the wall is of hyperbolicoutline, which is not shown in the drawing. In either case, there iscreated an annular space serving as overflow reservoir 18 of suchconfiguration that automatic filling thereof with fluid from thereservoir 6 is not possible. However, if fluid is displaced, forinstance by heating and expansion of the air in the reservoir 6, thenthis overflow reservoir 18 fills uniformly and without the inclusion ofany air from the rear end of reservoir 18 to the front end. Normally,only the narrowest portion of the eccentric annular groove 10 and theannular groove 12 receives ink. To assure that annular groove 10 isdefinitely provided with ink a capillary longitudinally extending groove29 (see FIG. 2) is provided at opposite sides of the longitudinallyextending groove 12 parallel thereto.

As has been pointed out, the portion or end wall 22 closes off thechamber 32. It is carried by the back portion 4 and is preferably aseparate member. It is provided with several longitudinally extendingribs 30 angularly spaced and of such height that several arcuatecapillary passages 31 are established between the bore of the backportion 4 and the peripheral face of wall 22, and it is these capillarypassages 31 which connect the annular capillary groove 20 with the inkreservoir 6. The annular capillary groove 20 is of constant crosssection since there is no shoulder at the joint between the bore of rearportion 4 and forward portion 5. The latter, as is evident from thedrawing, carries the ink applicator 28 with the tubular nib 27 and issecured thereto, preferably by means of screw threads.

The operation of the novel device will be obvious from what has beensaid before and from a consideration of the drawing. Ink flows from thereservoir 6 via the passages 31 through the annular capillary groove 20to the bore 26 in forward portion 5, and from there into the nib 27. Inthe area of bore 26 and of the nib 27 it flows about the Ipin 24, which,because of its movable arrangement, makes it possible to keep the bore26 of forward portion 5 and the interior of the tubular nib 27 free fromink encrustations in the simple manner described above without requiringdisassembly of the pen. Entry of ink into chamber 32 of guide sleeve 7is completely or substantially prevented since the bore 25 is so narrowthat it is filled by the pin 24. Replacement air for ink Withdrawn fromreservoir 6 fiows through air channel 16, the annular grooves 14 and 15which are connected with one another, and the subsequently arranged airchannel 17 into the overflow reservoir 18 between the front section 1and the back portion 4. From there it passes through the eccentricannular groove via the longitudinal groove 13 and the longitudinalgroove 12 and into the ink reservoir 6, breaking at intervals throughthe ink contained in the annular groove 10 and the longitudinal groove12.

It is not believed necessary to show how the ink reservoir 5 is filledsince this can be done in conventional form from an ink container or bymeans of cartridges. A cap will of course be provided for protecting thefront end of the pen and it should be noted that this can be placed ontothe pen without requiring removal of the ink applicator 28. The inkapplicator 28 can, of course, be replaced With a different type ofapplicator if desired.

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types of apen differing from the types described above.

While the invention has been illustrated and described as embodied inpens, it is not intended to be limited to the details shown, sincevarious modifications and structural changes may be made withoutdeparting in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can by applying current knowledgereadily adapt it for various applications without omitting featuresthat, from the standpoint `of prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this inventionand, therefore, such adaptations should and are intended to becomprehended within the meaning and range of equivalence of thefollowing claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. A pen comprising, in combination, an elongated pen barrel provided atits front end with a central bore and rearwardly therefrom with acentrally arranged closed cylindrical chamber having a narrow opening atits front end arranged coaxially with said central bore; an inkreservoir located in said barrel rearwardly of said cylindrical chamberand separated therefrom; wall means interposed between said inkreservoir and said cylindrical chamber and sealing the latter againstentry of ink from the former; passage means in said barrel including aportion extending alongside of and spaced from said cylindrical chambercommunicating at one end with said ink reservoir and at its other endwith said bore at said front end of said barrel; an ink applicatorremovably mounted on the front end of said barrel and provided With acentral passage arranged coaxially with said bore and said narrowopening; and a cleaning unit, including a piston element slidablyarranged within said cylindrical chamber and movable between a retractedposition nearer to said ink reservoir and an advanced position nearer tosaid narrow opening of said cylindrical chamber, said cleaning unit alsoincluding a pin secured at its rear end to and extending in forwarddirection from said piston element and projecting in advanced positionof the latter through said narrow opening and said bore in said frontend of the barrel into said central passage in said ink applicator.

2. A pen as defined in clairn 1, wherein said pin is of such length thatthe front end thereof in retracted position of said piston element islocated within said central bore in the front end of said barrel.

3. A pen as defined in claim 1, wherein the crosssectional area of saidcentral bore is greater than the cross-sectional area of said narrowopening.

4. A pen as defined in claim 2, wherein said pin is of such length thatthe front portion thereof in advanced position of said piston element islocated within said central passage of said ink applicator.

5. A pen as defined in claim 1, wherein said barrel comprises a rearsection within which said ink reservoir is located, and a front sectionremovably secured to said rear section and comprising said frontportion.

6. A pen as defined in claim 5, wherein said front section includes anouter sleeve member secured to said rear section and having an openfront end, and an inner sleeve having a back portion received in saidouter sleeve with peripheral clearance so as to define therewith anannular space and also having a forward portion connected to said backportion partially located within said outer sleeve and sealing saidannular space and partially projecting outwardly beyond said open frontend of said outer sleeve.

7. A pen as defined in claim 6, said inner sleeve further comprising aguide sleeve received within said forward and back portions of saidinner sleeve and defining therewith said portion of said passage means,said piston element being located within said guide sleeve.

8. A pen as defined in claim 7, wherein said passage means is an annularcapillary passage of constant crosssection.

9. A pen as defined in claim 7, and further comprising centering meansfor centering said inner sleeve with respect to said outer sleeve.

10. A pen as defined in claim 1, wherein said passage means comprises aplurality of capillary channels communicating with said ink reservoirand with said portion of the passage means.

References Cited UNITED STATES PATENTS 2,891,512 6/1959 Kovacs 4011-258X FOREIGN PATENTS 1,244,806 9/ 1960y France.

LAWRENCE CHARLES, Primary Examiner.

